1. Field of the Invention
The present invention relates to a micro-sensor, and more particularly to a micro-sensor having a flexible circuit board.
2. Related Art
When patients take an endoscopic examination, two kinds of instruments are generally used. One kinds of instrument is a traditional endoscope, in which one end of a long black tube is connected to a machine having a cold-light source that is capable of generating cold lights, and the tube contains the optic fibers therein. The optic fibers is capable of transferring the cold lights to the other end of the tube. During examination, the tube is inserted into an organ to be examined, cold lights from the cold-light source illuminates the interior of the organ, and then a photo sensor chip disposed on the end of the tube transfers clear image signals back to the machine. A computer in the machine then converts the signals into images. The other one kinds of instrument is a capsule endoscope, which is a micro image pick-up device, and it is as small as a capsule. The capsule endoscope includes a photo sensor chip, a light emitting diode (LED), a battery, and a wireless transmitter, and so on. Many organs in a human body cannot be easily examined through an endoscope. A, The endoscope is also difficult to be manipulated as the traditional endoscope is excessively long. For example, small intestine is a narrow winding path zigzagged in the abdominal cavity. A rigid tube is inserted in the winding intestine and wound there along may unavoidably hurts the soft and tender intestine more or less. Therefore, physicians may use capsule endoscope to replace traditional endoscopes.
Regardless of the traditional endoscope or the capsule endoscope, a micro-sensor is used to sense image signals. Referring to FIG. 1, it is a schematic view of a conventional micro-sensor. The conventional micro-sensor 10 includes a circuit substrate 1, a plurality of wiring duct structures 2, and an image sensing device 3. The circuit substrate 1 has metal wires 4 formed thereon, and the plurality of wiring duct structures 2 is formed on a side of the micro-sensor 10. The image sensing device 3 is disposed on the circuit substrate 1 and electrically connected to one end of the metal wires 4. The other end of the metal wires 4 is exposed out of the plurality of wiring duct structures 2 for being connected to a plurality of transmission lines corresponding to the plurality of wiring duct structures 2, so as to transfer the image signals. The conventional micro-sensor 10 is restricted in volume, and thus the volume of the adopted circuit substrate 1 is correspondingly limited. Furthermore, the processes of manufacturing a plurality of wiring duct structures 2 on the circuit substrate and connecting the plurality of transmission lines to the end of the metal wires 4 exposed out of the plurality of wiring duct structures 2 may further increase the difficulty in manufacturing the micro-sensor 10. Therefore, additional auxiliary equipments are generally required for such manufacturing process, and as a result, the manufacturing process is both labor-consuming and time-consuming. The manufacturing cost cannot be reduced.